요즘 나오는 App들은 Navigation Drawer를 사용한 UX가 많습니다.

Google Developer 사이트에서 훌륭한 예제 코드를 다루고 있는데, 여기서는 Android Studio에서 자동으로 생성해준 템플릿 코드 기반으로 간단하게 구현을 해보았습니다.

먼저 메뉴 항목들을 나열할 xml 파일을 만들어줍니다. (res 폴더 아래 menu 폴더 아래 만들어 주시면 됩니다.)

activity_main_drawer.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">

  <group android:checkableBehavior="single">
    <item
      android:id="@+id/menu_bt_server"
      android:icon="@drawable/ic_menu_camera"
      android:title="Bluetooth Server" />
    <item
      android:id="@+id/menu_bt_client"
      android:icon="@drawable/ic_menu_gallery"
      android:title="Bluetooth Client" />

  </group>

</menu>

그리고, 액티비티에서 사용할 레이아웃은 다음과 같이 작성합니다.

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  xmlns:tools="http://schemas.android.com/tools"
  android:id="@+id/drawer_layout"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:fitsSystemWindows="true"
  tools:openDrawer="start">

  <include
    layout="@layout/app_bar_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

  <android.support.design.widget.NavigationView
    android:id="@+id/nav_view"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:fitsSystemWindows="true"
    app:headerLayout="@layout/nav_header_main"
    app:menu="@menu/activity_main_drawer" />

</android.support.v4.widget.DrawerLayout>

app_bar_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  tools:context="snowdeer.bluetooth.sample.MainActivity">

  <android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay">

    <android.support.v7.widget.Toolbar
      android:id="@+id/toolbar"
      android:layout_width="match_parent"
      android:layout_height="?attr/actionBarSize"
      android:background="?attr/colorPrimary"
      app:popupTheme="@style/AppTheme.PopupOverlay" />

  </android.support.design.widget.AppBarLayout>

  <RelativeLayout
    android:id="@+id/content_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior" />

</android.support.design.widget.CoordinatorLayout>

nav_header_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="@dimen/nav_header_height"
  android:paddingTop="@dimen/activity_vertical_margin"
  android:paddingBottom="@dimen/activity_vertical_margin"
  android:paddingLeft="@dimen/activity_horizontal_margin"
  android:paddingRight="@dimen/activity_horizontal_margin"
  android:background="@drawable/side_nav_bar"
  android:gravity="bottom"
  android:orientation="vertical"
  android:theme="@style/ThemeOverlay.AppCompat.Dark">

  <ImageView
    android:id="@+id/imageView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:paddingTop="@dimen/nav_header_vertical_spacing"
    app:srcCompat="@android:drawable/sym_def_app_icon" />

  <TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:paddingTop="@dimen/nav_header_vertical_spacing"
    android:text="Android Studio"
    android:textAppearance="@style/TextAppearance.AppCompat.Body1" />

  <TextView
    android:id="@+id/textView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="android.studio@android.com" />

</LinearLayout>

그리고 실제 Java 코드는 다음과 같이 작성하면 됩니다.

MainActivity.java

public class MainActivity extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
        this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.setDrawerListener(toggle);
    toggle.syncState();

    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);

    replaceServerFragment();
  }

  @Override
  public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
      drawer.closeDrawer(GravityCompat.START);
    } else {
      super.onBackPressed();
    }
  }

  @SuppressWarnings("StatementWithEmptyBody")
  @Override
  public boolean onNavigationItemSelected(MenuItem item) {
    int id = item.getItemId();

    if (id == R.id.menu_bt_server) {
      replaceServerFragment();
    } else if (id == R.id.menu_bt_client) {
      replaceClientFragment();
    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
  }

  void replaceServerFragment() {
    setTitle("Bluetooth Server");
    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    Fragment fragment = new BTServerFragment();
    ft.replace(R.id.content_main, fragment);
    ft.commit();
  }

  void replaceClientFragment() {
    setTitle("Bluetooth Client");
    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    Fragment fragment = new BTClientFragment();
    ft.replace(R.id.content_main, fragment);
    ft.commit();
  }
}